This invention concerns an improvement in loose pin butt hinges which are commonly attached along edges of doors and along complementary positions on door jams to hang doors.
The butt hinges usually have first and second plates with countersunk holes for receiving flat head screws or bolts for fixing the plates to the doors or jams. Plates are usually rectangular and usually fit on outer edges of doors and inner edges of jams. The plates may be similarly shaped or differently shaped. While it is usual to shape the plates as rectangles, one or both of the plates may have a triangular or other strap-like shape.
On swinging doors, butt hinges may be arranged with intermediate plates hinged between fixed plates.
In constructing butt hinges, it is traditional to construct one plate with an even number of knuckles or cylinders and another plate with an odd number of knuckles or cylinders, which interfit and align with the knuckles and cylinders of the first plate. It is conventional to construct one of the plates with three knuckles or cylinders and the other plate with two knuckles or cylinders, which respectively fit in spaces between the outer and center knuckles of the first plate. One plate may be fixed to a door jamb, the other fixed to a door.
It is conventional to construct the knuckles or cylinders in such a way that they project out from the door jamb, usually on the inside of the door so that the door swings open toward the room or space being entered. In conventional butt hinges, the knuckles are formed from extensions of the plate, which are turned and formed as cylinders. Alternatively, cylinders may be welded along edges of the plate.
Some butt hinges are constructed with decorative false pinheads inserted in lower ends of lower cylinders. Those decorative false pinheads remain fixed during the life of the hinge. In butt hinges which do not have the preexisting false pin heads, the hinges may be reversible so that the upper edge and lower edge are interchangeable.
Removable pin butt hinges are commonly used to hang doors, because the hinges are durable and dependable, and generally function effectively for the entire duration of the structure in which they are installed. Functionally, they are excellent; except that, by reason of structural design, they generally cause a singular but serious problem when for some reason a door must be temporarily removed. The problem is that where doors have been mounted for several years, both doors and hinges are painted many times, and while this does not affect their opening and closing, the accumulation of paint does bind the top of the hinge-pin to the uppermost knuckle of the hinge, almost like a steel weld, which makes it a horrible task to extract the pin for the removal of the door. Pin extraction is difficult because a tool such as a screwdriver must be driven between the crown of the pin and the adjacent surface of the hinge cylinder. A need exists for butt hinges or door hinges with more easily removable pins.